Supreme leader Ayatollah Ali Khamenei urged Iranians on Wednesday to stay united. “Everyone should be vigilant, because our enemy America is sly and evil… and may have plans for 2019,” Khamenei said. “But we are stronger than them and they will fail as they have in the past,” according to the text of a speech which was posted on his website. “My advice to the Iranian nation, especially the youth and the country’s various organizations, professional or political, is to be careful and not make matters easier for the enemy,” Khamenei said, as cited by Reuters. Tehran has accused the US, Israel, regional rival Saudi Arabia and government opponents living in exile, of fomenting unrest in the country.